[unreadable] Given their history of family adversity, foster children are a high-risk population for negative sibling [unreadable] relationships and frequent physical aggression toward a sibling leading to increased risk for [unreadable] physical aggression toward other children i.e., non sibling peers. The foster placement context [unreadable] provides a critical window for timely and amenable youth violence prevention to alter the [unreadable] downward behavioral trajectories of children with histories of neglect. This study uses the [unreadable] context of the sibling relationship to develop and evaluate the effectiveness of a youth violence [unreadable] prevention intervention. The goal of this application is to reduce sibling aggression which is [unreadable] prevalent in neglected children placed in foster homes and forecasts significant risk for youth [unreadable] violence. Sibling aggression among maltreated children remains a highly under identified and [unreadable] untreated problem. The failure to intervene represents a major public health concern. This [unreadable] intervention utilizes a tran-stheoretical model that implicates child vulnerabilities (altered cortisol [unreadable] and emotion dysregulation), sibling pair risk- (low positively, and poor conflict management), and [unreadable] foster parent- (non mediation) factors into a testable intervention model to decrease risk for sibling [unreadable] and peer physical aggression among young neglected children. The 'Promoting Sibling Bonds' [unreadable] intervention combines two promising short-term psychosocial sibling programs: Sibs Together [unreadable] (Bank, 2000; 2004) and Mediation-Based Intervention Strategy for Sibling Conflict (Smith & Ross, [unreadable] 2007) adapted to meet the needs of neglected children in the foster care system. The study [unreadable] involves two phases. In Phase 1 Intervention Development, we will refine and expand the [unreadable] intervention protocol, adapt and integrate manuals, train therapists (interventionists), make [unreadable] changes from iteration work, and try-out behavioral outcome measures. In Phase 2 [unreadable] Implementation of a controlled trial, we will recruit a sample of N = 144 children (nested in 72 [unreadable] pairs) between ages 5-8 years old; collect baseline data (wave1); randomize sibling pairs and [unreadable] their families (foster parent or biological parent for cases who reunite) to intervention and [unreadable] comparison groups, and collect post-intervention (wave2) and 6 months follow-up (wave3) [unreadable] outcome data of the adapted intervention. We hypothesize that at post-intervention (wave2), and [unreadable] again at follow-up (wave3), as compared to children assigned to the comparison 'usual care [unreadable] '(UC), children assigned to the experimental intervention condition (IC) will show improvement in [unreadable] reported sibling aggression, non sibling peer aggression, emotion dysregulation; and children will [unreadable] be more likely to exhibit a typical diurnal cortisol pattern. Sibling pairs will show improved [unreadable] relationship quality (positivity and negativity). The proportion of foster parents and sibling pairs [unreadable] who engage in conflict mediation, compromise, and reconciliation strategies will be higher in the [unreadable] intervention group. The public health impact of this intervention for violence prevention is high. [unreadable] Our innovative outcome model is a part of a second generation of studies aimed at integrating rich [unreadable] behavioral science and advances in neurobiology to better understand the multilevel change [unreadable] mechanisms in prevention trials. [unreadable] [unreadable] [unreadable] [unreadable] [unreadable] [unreadable] [unreadable] [unreadable] [unreadable]